From 9aa31157d59fb0f993ea831227dbc29bab64e7e4 Mon Sep 17 00:00:00 2001
From: Nico Weber <thakis@chromium.org>
Date: Tue, 27 Feb 2024 09:09:09 -0500
Subject: [PATCH] LibPDF: Use right encoding for standard fonts Symbol and
 ZapfDingbats

We use Liberation Sans for the actual glyph for these, and that's
missing some (Symbol) / all (ZapfDingbats) of the glyphs we need
for these two standard fonts (...or at least the mapping from
name to glyph, not sure). But still, better rendering squares than
completely incorrect glpyhs.

Our code deciding what to do when a value isn't found in an encoding,
or when the name doesn't map to a glpyh, also needs work, but that's
mostly independent of this change. I think this is a nice small
standalone progression.
---
 Userland/Libraries/LibPDF/Fonts/Type1Font.cpp | 24 +++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/Userland/Libraries/LibPDF/Fonts/Type1Font.cpp b/Userland/Libraries/LibPDF/Fonts/Type1Font.cpp
index 671047d449..82913c0fff 100644
--- a/Userland/Libraries/LibPDF/Fonts/Type1Font.cpp
+++ b/Userland/Libraries/LibPDF/Fonts/Type1Font.cpp
@@ -54,8 +54,28 @@ PDFErrorOr<void> Type1Font::initialize(Document* document, NonnullRefPtr<DictObj
         auto font = TRY(replacement_for(base_font_name().to_lowercase(), font_size));
 
         auto effective_encoding = encoding();
-        if (!effective_encoding)
-            effective_encoding = Encoding::standard_encoding();
+        if (!effective_encoding) {
+            // PDF 1.7 spec, APPENDIX D Character Sets and Encodings
+            // "Sections D.4, “Symbol Set and Encoding,” and D.5, “ZapfDingbats Set and Encoding,”
+            //  describe the character sets and built-in encodings for the Symbol and ZapfDingbats (ITC Zapf Dingbats)
+            //  font programs, which are among the standard 14 predefined fonts. These fonts have built-in encodings
+            //  that are unique to each font. (The characters for ZapfDingbats are ordered by code instead of by name,
+            //  since the names in that font are meaningless.)"
+            // FIXME: We use Liberation Sans for both Symbol and ZapfDingbats. It doesn't have all Symbol
+            //        characters, or at least not under the codepoints used in AdobeGlpyhList. It doesn't
+            //        have any ZapfDingbats characters, or at least not the names for it. Not sure what to do about
+            //        this -- we either need a different font, or need to tweak the encoding somehow.
+            //        (For Helvetica / Times / Courier, the Liberation family doesn't have the right metrics.)
+            if (base_font_name() == "Symbol"sv)
+                effective_encoding = Encoding::symbol_encoding();
+            else if (base_font_name() == "ZapfDingbats"sv)
+                effective_encoding = Encoding::zapf_encoding();
+            else
+                effective_encoding = Encoding::standard_encoding();
+        }
+
+        // FIXME: For the standard 14 fonts, set some m_flags bits (symbolic/nonsymbolic, italic, bold, fixed pitch, serif).
+
         m_fallback_font_painter = TrueTypePainter::create(document, dict, *this, *font, *effective_encoding);
     }